As clinicians are forced to decrease time spent with patients and the specialization and fragmentation of care increases, patients are required to play an increasingly prominent role in their health care. Yet, few information tools exist to support patients in this active role. In particular, patients often must coordinate their health care across multiple clinicians, learn new health terminology, make treatment choices, manage their home care, track insurance benefits, etc. At the same time, patients are trying to maintain their normal professional and personal lives, but the intense information management demands placed on them can interfere with all those activities. Little is known about this information management work of patients, but such knowledge must be a first step towards developing the tools that patients need to support their active role. The long-term objective of this research is both to understand patients'information management work and to develop new technology that will support that work. Specifically, we propose to (1) develop a model of patients'personal health information management work, (2) develop new technology that supports patients in that work, and (3) evaluate the effectiveness of our new technology in helping patients manage their personal health information, participate in their own health care, and maintain their daily life activities. Our study design is distinctive because we include patients in all facets of our research, including field studies of patients'information work in the home and the clinic, collaborative technology design of new information technology to support patients'work, and evaluation of the technology in the home.